COOPERSTOWN - Last Sunday was one of the few weekends this summer the Cherney Maribel Caves County Park cave system was open for public tours.

This park, just about a mile from Interstate 43 in Manitowoc County, is open throughout the spring and summer and offers a number of lovely caves to explore. Some caves, including Maribel New Hope Cave and the Tartarus Cave System, are gated and are only accessible on select weekends.

Cherney Maribel Caves are only one of five “show caves” in the state of Wisconsin. Other well-known systems include for-profit Cave of the Mounds in southwestern Wisconsin and the Calumet County Parks’ Ledgeview Nature Center in Chilton.

The Maribel caves were founded 21 years after the county park was opened in 1963, as the first park in Manitowoc County.

Wisconsin Speleological Society Vice Chairman Bryan Kleist, left, and Board Member Gary Soule climb to the entrance of the Tartarus Cave System at Cherney Maribel Caves County Park on Saturday, July 16 in Maribel. The county park's Maribel New Hope Cave is open to the public and have guided tours on the third Sunday of every month from May to September.(Photo: Yi-Chin Lee/USA TODAY NETWORK-Wi)

Walking the trails, visitors can observe gorgeous dolomite formations, which are part of the sweeping Niagara Escarpment, and view the West Twin River, which sidles up to the east side of the park.

Volunteer members of the Wisconsin Speleological Society have been working with the Manitowoc County Parks and Planning Commission to excavate the caves of sediment deposited by the glaciers 10,000-12,000 years ago. The removed sediment is being recycled to develop trails within the park.

Originally, four caves were found in the park, and there are eight known ones today. These are found through the excavation process. By excavating, natural habitats can be restored, and the public has the opportunity to view some delicate geological features and underground ecosystems.

“Caves are some of the last frontiers on Earth,” WSS Grotto Historian Gary K. Soule said. “Some of our volunteers have been in caves in this park that have seen fewer people than the moon.”

Vandalism of the caves has been a problem for years, WSS Vice Chairman Bryan Kleist said. On July 13, someone entered the Maribel New Hope Cave by cutting a lock off a secured door. The person or people involved extensively damaged the cave by breaking off the natural formations and removed them from the cave.

A so-called Bacon Strip Stone could be found in many locations in the Marble New Hope Cave in Cherney Maribel Caves County Park on Saturday, July 16. The cave is open to the public and have lighted, guided tours on the third Sunday of every month from May to September. (Photo: Yi-Chin Lee/USA TODAY NETWORK-Wi)

“We’ve had people break into the sealed caves in the past, and we’ve lost stalactites, we’ve even had fluorescent green paint sprayed on the walls,” Kleist said.

Manitowoc County Parks Superintendent Gary Robinson said the vandalism from earlier this month had stalactites, flow stone and other geological formations broken or stolen.

“Stalactites grow about an inch every hundred years. Some of these were 4 and 5 inches long, now gone,” Robinson said. “The flow stone is from glacial events and may be seen in 10,000 years, but truly it is gone forever for no one to enjoy.”

Robinson said Cherney is a public park that belongs to everyone, and we need to help take care of them for future generations to enjoy. The Manitowoc County Sheriff’s Office is offering up to a $500 reward for information leading to the arrest of the vandals.

“These formations are unique to the glacial events that have occurred through thousands of years, and now your kids and families and brothers, sisters and travelers from everywhere will never get to enjoy because of the selfish and thoughtless acts of a few,” Robinson said.

Despite the vandalism, the County Parks Department and volunteers from WSS have been working hard to continue updating the park for visitors. The parking lot is being expanded to service the growing number of tourists to the park, and there has been a strong push to bring electricity to the park, specifically into the caves themselves.

In addition to dealing with vandals, the park is also recovering for the 2013 tornado, which severely damaged park trails and buildings.

Things are looking up, however, with the new additions and large number of visitors. In June, more than 400 people toured the caves. Families can enjoy the park by exploring the caves, cooking a picnic lunch, playing on the playground or riding the bike trails.

“It is unheard of to have a cleared cave in this part of Wisconsin, as they are pretty hard to find,” Soule said. “The nice part is we’re always finding new caves, so people come back to the park to see what is new.”

The tours are limited to one weekend a month during the summer because the Maribel New Hope Cave must be drained of water for people to safely enter. Volunteers are needed as tour guides, parking attendants, excavators and more. Contact head volunteer Mike Sobush at 920-860-6123.

This story is a part of the Making Manitowoc series of stories that highlight interesting people, places and more in the county that make it one-of-a-kind. If you know of an interesting person, place or thing made in Manitowoc that you think could be featured, contact Alyssa Bloechl at 920-686-2152, email abloechl@htrnews.com or Twitter @alyssabloechl.

If you go:

What: Cherney Maribel Caves County Park

When: 6 a.m.-8 p.m., April 1-Oct. 31

Cave Tours: 10 a.m.-3 p.m., Aug. 21, Sept. 18 and Oct. 9

Cost: Free, donations of $5 or more will earn tourists a commemorative patch. Donations help pay for light fixtures and other tools.